Phase-distribution system



T. F. BAILY AND F. T. COPE.

PHASE DISTRIBUTION SYSTEM. APPLICATION FILED JUNE 27. I918.

' 1,353,983. Patented Sept. 28, 1920.

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gray/ HTTOP/VEV UNITED STATES PATENT orrics.

THADDEUS F BAILY AND FRANK T. COPE, 0F ALLIANCE, OHIC, ASSIGNORS TO THE ELECTRIC FURNACE COMPANY, OF ALLIANCE, 0310, A CORPORATION OF OHIO,

rnesn-nrsrmrurron SYSTEM.

To all whom it-may concern:

Be it known that we, THADDEUS F. BAILY and FRANK T. Corn, citizens of the United States, both residin at Alliance, in the county of Stark and State of Ohio, have invented a new and useful Phase-Distribution System, of which the following is a specification. Y

This invention'relates to phase distribution systems and especially to a systemby which a three phase current may be employed in the operation of an electric furnace of the resistance type.

The object of our invention is to employ a three phase current for operation of an electric furnace of the resistance type designed for a single or two phase current.

Another object is to construct a system which will employ all three phases of a three phase line for the .operation of an electric furnace of the three phase type designed for a single or two phase current and at the same time obtain an equal distribution of voltage to the resisterel'ements within the furnace.

With .these objects in view the invention consists in the novel construction and arrangementof parts, hereinafter described, illustrated in the accompanying drawlngs, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of construction may. be made within the scope of the appended claims, without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawings, we have shown a diagrammatic view of a three phase line and the transformer system which we desireto employ in the operation of a single phase furnace.

Similar numerals of reference indicate corresponding parts throughout the several figures'of the drawings.

For obvious reasons it is more convenient to construct electric furnaces of the resistance type to be operated upon a single phase current, but since the only current obtainable from the power companies is frequently of three phase, it is necessary to unbalance the line in connectingafurnace by simply employing one or two phases.

In order to overcome this difficulty we have designed the herewith illustrated s stem by the use of which all three phases of the sup- Speeiflca'tion of Letters Patent. Pat t d Sept. 28 1920'. Application filed June 27,

1918. Serial in. 242,165.

, mary coil 2 of a three to two phase transformer, the remaining phase connecting to the primary coil 3 of a second three to .two phase transformer. The primary coils 2 and 3 are joined by the connection 4 which is attached to the coil 2 at its exact center and to the coil 3 ate point 86.6% from one extremity and 13.4% from the other. To those skilled in the art this construction is known as the Scott connected transformer.

. A secondary coil 5 which cooperates with the coil 2 is connectedby the wire 6 to one electrode of the resistance element 7 within the furnace. The circuit is completed bythe wire 8 which makes the return to the secondary coil 5 through the nine point sliding contact switch 9. A secondary coil 11 is arranged to cooperate with the coil 3 and is likewise connected by a wire 12 to the other that we propose to employ all three phases evenly and deliver to each resister element within the furnace an equal amount of current.

While we'have shown for purpose of illustration our system as appliedto a furnace having two resister elements it is obvious that two single phase furnaces each containing one resister element could be operated at the same temperature by our system.

Having fully 'described our invention what we claim as new and desire to secure by Letters Patent is:

1. In a phase distribution system, the combination with a pair of electric resistance elements, each resistance element provided with a pair of electrodes of a three phase supply formers being Scott connected, a seconda'ry coil cooperating with the primary coil of each transformer and a connection between the electrodes of each resistance element and the adjacent secondary coil.

'w-ith a pair of electrodes, of a three phase supply line, two phases connected to the primary coil, of a three to two phase transformer, the remaining phase connected to the primary coil of a second three to two phase transformer, the primary coils of said trans formers being Scott connected, a secondary coil cooperating with the primary coil oieach transformer, a connection between one electrode of eachresistance element and the adjacent secondary coil and a multiple point sliding switch connection between the 15 other electrode of each resistancev element and the adjacent secondary coil.

In testimony that we claim the above,-we have hereunto subscribed our names.

THADDEUS FQBA ILY. FRANK T. corn 

